<?php
/***********************************************************************************
 * X2Engine Open Source Edition is a customer relationship management program developed by
 * X2 Engine, Inc. Copyright (C) 2011-2019 X2 Engine Inc.
 * 
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Affero General Public License version 3 as published by the
 * Free Software Foundation with the addition of the following permission added
 * to Section 15 as permitted in Section 7(a): FOR ANY PART OF THE COVERED WORK
 * IN WHICH THE COPYRIGHT IS OWNED BY X2ENGINE, X2ENGINE DISCLAIMS THE WARRANTY
 * OF NON INFRINGEMENT OF THIRD PARTY RIGHTS.
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU Affero General Public License along with
 * this program; if not, see http://www.gnu.org/licenses or write to the Free
 * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301 USA.
 * 
 * You can contact X2Engine, Inc. P.O. Box 610121, Redwood City,
 * California 94061, USA. or at email address contact@x2engine.com.
 * 
 * The interactive user interfaces in modified source and object code versions
 * of this program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU Affero General Public License version 3.
 * 
 * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
 * these Appropriate Legal Notices must retain the display of the "Powered by
 * X2 Engine" logo. If the display of the logo is not reasonably feasible for
 * technical reasons, the Appropriate Legal Notices must display the words
 * "Powered by X2 Engine".
 **********************************************************************************/




/**
 * Deletes oldest records if count surpasses limit
 */
class RecordLimitBehavior extends CActiveRecordBehavior {

    /**
     * @var int $limit max number of records
     */
    public $limit; 

    /**
     * @var string $timestampField will be used to find oldest record 
     */
    public $timestampField; 

    public function afterSave ($event) {
        if (!is_numeric ($this->limit)) return;
        if ($this->getStaticModel ()->count () > $this->limit) {
            $oldestRecordId = Yii::app()->db->createCommand ()
                ->select ("id")
                ->from ($this->owner->tableName ())
                ->where (
                    "{$this->timestampField}=(
                        SELECT MIN({$this->timestampField})
                        FROM {$this->owner->tableName ()}
                    )")
                ->queryScalar ();

            $oldest = $this->getStaticModel ()->findByPk ($oldestRecordId);
            if ($oldest) {
                $oldest->delete ();
            }
        }

    }

    private $_staticModel;
    private function getStaticModel () {
        if (!isset ($this->_staticModel)) {
            $class = get_class ($this->owner);
            $this->_staticModel = $class::model ();
        }
        return $this->_staticModel;
    }

}

?>
